irc: fix uncontrolled format string when sending unknown irc commands (if option irc.network.send_unknown_commands is on)

ChangeLog

@@ -60,6 +60,8 @@ Version 0.4.1 (under dev!)
   list with arguments inside), guile >= 2.0 is now required (bug #38350)
 * guile: fix crash on calls to callbacks during load of script (bug #38343)
 * guile: fix compilation with guile 2.0
+* irc: fix uncontrolled format string when sending unknown irc commands
+  (if option irc.network.send_unknown_commands is on)
 * irc: fix uncontrolled format string when sending ison command (for nicks
   monitored by /notify)
 * irc: fix refresh of nick in input bar when joining a new channel with op

src/plugins/irc/irc-input.c

@@ -205,7 +205,7 @@ irc_input_data (struct t_gui_buffer *buffer, const char *input_data, int flags)
             if (ptr_server)
             {
                 irc_server_sendf (ptr_server, flags, NULL,
-                                  weechat_utf8_next_char (input_data));
+                                  "%s", weechat_utf8_next_char (input_data));
             }
             return WEECHAT_RC_OK;
         }